A boat day is a measure of fishing effort (e.g. example, ten vessels in a fishery, each fishing for fifty days, would have expended five hundred boat-days of effort). (Please refer to the FAO Fisheries Glossary at http://www.fao.org/fi/glossary/default.asp [last accessed: June 19th 2009])

To catch: to undertake any activity that results in taking fish (sensu lato) out of its environment dead or alive. To bringing fish on board a vessel dead or alive. Modified from FAO (1998): Guidelines for the routine collection of capture fishery data. FAO Fish. Tech. Pap, 382: 113 p.

Catch: The total number (or weight) of fish caught by fishing operations.

Catch should include all fish killed by the act of fishing, not just those landed. Restrepo V. (1999): Annotated Glossary of Terms in Executive Summary Reports of the International Commission for the Conservation of Atlantic Tunas´ Standing Committee on Research and Statistics (SCRS). ICCAT.The catch is usually expressed in terms of wet weight. It refers sometimes to the total amount caught, and sometimes only to the amount landed. The catches which are not landed are called discards. Cooke, J.G. (1984), Glossary of technical terms. In Exploitation of Marine Communities, R.M. May (ed), Springer-Verlag